1. Field of the Invention
The present invention is related to a rivet tool, and more particularly to a rivet tool capable of measuring size of blind rivet.
2. Description of the Related Art
Blind rivets are used to fasten workpieces with a rivet tool. The advantage of using the blind rivets to fasten workpieces is that a user can operate the rivet tool at one side of the workpieces to be fastened without having to see or access the other side of the workpieces.
A blind rivet has a rivet body and a mandrel. The demarcate sizes of regular blind rivets are determined by sizes of the rivet bodies instead of those of the mandrels. The sizes of the rivet bodies are 3/32″ (2.4 mm), ⅛″ (3.2 mm), 5/32″ (4.0 mm), 3/16″ (4.8 mm) and ¼″ (6.4 mm) according to specifications of American Industrial Fasteners Institute (IFI), while the sizes of the rivet bodies are 2.4 mm, 3.0 mm, 3.2 mm, 4.0 mm, 4.8 mm, 5.0 mm, 6.0 mm and 6.4 mm according to International Organization for Standardization (ISO).
In collaboration with the use of blind rivets, rivet tool is an indispensable tool for fastening blind rivets on workpieces. Usually, the mandrel is inserted into a working nosepiece of the rivet tool and the rivet body is inserted into the prepared hole of workpieces. The rivet tool grips and pulls the shank of the mandrel to draw the rivet body, so that the rivet body is compressed and expanded to fasten on the workpieces. The mandrel is snapped off and the rivet body is tightly fastened the workpieces in the end.
When blind rivets are shipped out of factories, rivet bodies having identical size are packed in a same package and marked with the sizes of the rivet bodies. Matching blind rivets and nosepieces must be identified before a rivet tool can correctly and smoothly draw the blind rivets. However, as blind rivets are not marked with size thereon, the unpacked and mixed blind rivets with various sizes could cause trouble in identifying matching blind rivets to use unless users are experienced and familiar with the related field.
If users fail to identify matching blind rivets and nosepieces to use, blind rivets would fail to be correctly drawn and fastened. For example, if the size of a rivet body is 4.0 mm (the diameter of the matching mandrel is less than 2.41 mm) and the mandrel for the 4.0 mm rivet body is inserted into a working nosepiece corresponding to the mandrel for a 3.2 mm rivet body (the maximum inner diameter could be 2.41 mm and up), the mandrel of the 4.0 mm blind rivet may still remain inserted into the working nosepiece for the 3.2 mm rivet body, while the broken mandrel could be jammed in the working nosepiece of the rivet tool without being able to be ejected. On the contrary, if a size of a rivet body is 4.0 mm and the mandrel for the 4.0 mm rivet body is inserted into a working nosepiece matching for the mandrel corresponding to a 4.8 mm rivet body, the mandrel may not be easily gripped and fast snapped off, thereby failing to successfully break the mandrel and expedite the fixing job of workpieces.
Accordingly, once the sizes of blind rivets and working nosepieces are not matching, the blind rivets not only cannot be rapidly drawn and fastened, but also many blind rivets are wasted or rivet tools need to be repaired for being jammed by the broken mandrel. Due to unmarked specification on blind rivets, except through related professional craftsmen, the problem that users cannot directly and promptly pick right blind rivets to use needs to be refined.